The user of a mobile phone sometimes becomes unaware of an incoming call or electronic mail in a house because it tends to put its mobile phone on a desk or shelf, though it usually carries the mobile phone with it when going out. In view of this, various techniques for informing the user of the incoming to the mobile phone have been proposed. Japanese Unexamined Patent Application Publication No. 2002-359670A discloses in paragraph 0007 an alerting system for transmitting incoming alerting information from a mobile phone having a short-range wireless communication function to a television having the short-range wireless communication function of the same standards as the mobile phone to put necessary display on the television. On the other hand, Japanese Unexamined Patent Application Publication No. 2003-304304A discloses in claim 1 an incoming alerting display device for receiving radio waves transmitted from the mobile phone indicating receipt of an incoming call or electronic mail to the mobile phone to display the information on the television that the call or electronic mail is received.
The device of JP No. 2003-304304A requires that the television be provided with an antenna or receiving circuit for receiving the radio waves transmitted from the mobile phone indicating receipt of the incoming call or electronic mail. On the other hand, the system of JP No. 2002-359670A requires that both the mobile phone and the television have the short-range wireless communication function of the same standards. Further, in both JP No. 2003-304304A and JP No. 2002-359670A, the user is not informed of the incoming call or electronic mail when the power of the television is off because the incoming alert information of the mobile phone is not displayed on the television.